If you fill a 1 L bottle with water and another 1 L bottle without rubbing alcohol, which bottle would feel heavier?

The oxidizing agent our bodies use to obtain energy from food is oxygen (from the air). if you breathe 15 times a minute (at rest), taking in and exhaling 0.5 l of air with each breath, what volume of air do you breathe each day? air is 21% oxygen by volume. what volume of oxygen do you breathe each day?

Most animal cells membranes have proteins that pump ions out of the cell and potassium ions into the cell

20 the compound al(nh3)2 has atoms of nitrogen.